Psychopaths have poor sense of smell

There may be an easy way to discover whether your boss really is the psychopath you think he is - just ask him to help you choose aftershave.

Scientists have discovered that people with psychopathic tendencies have a poor sense of smell, which they say points to inefficient processing in the front part of the brain.

Psychopathy is a severe personality disorder that's pretty much what you think it is: callousness, manipulation, sensation-seeking and antisocial behavior.

Previous studies have shown that people with psychopathic traits have impaired functioning in the front part of the brain - the area largely responsible planning, impulse control and acting in accordance with social norms.

But this part of the brain is also involved in a person's sense of smell, prompting the new research.

Mehmet Mahmut and Richard Stevenson, from Macquarie University in Australia, tested 79 non-criminal adults living in the community, looking at whether a poor sense of smell was linked to higher levels of psychopathy.

And they found that people who scored highly on psychopathic traits were more likely to struggle to both identify smells and tell the difference between different ones.

The authors conclude that their discovery could help diagnose psychopaths, as one's ability to smell is hard to fake.

"Olfactory measures represent a potentially interesting marker for psychopathic traits, because performance expectancies are unclear in odor tests and may therefore be less susceptible to attempts to fake good or bad responses," they say.